Li Na demolishes Flavia Penetta

Bouchard now has to regroup for a semi-final against world number four Li Na after she swept aside Italian Flavia Pennetta in a one-sided, straight-sets demolition earlier on Tuesday.

The Chinese trailblazer was in dominant form as she crushed the 28th seed 6-2, 6-2 to set up a last-four clash with either Serbia's Ana Ivonovic or up-and-coming Canadian teen Eugenie Bouchard.

Li is starting to peak at the right time, with the 67-minute mauling of Pennetta coming after she smashed Ekaterina Makarova in less than an hour on Sunday.

It followed a verbal volley by coach Carlos Rodriguez after her third-round endeavour, where she was taken to three sets and saved a match point against Lucie Safarova.

"After I saved match point (against Safarova) I have got better, I got a lot of confidence from that and I believe in myself," said Li.

"I feel good, I always play well here and I hope I can take one more step this year."

The two-time Melbourne finalist and 2011 French Open winner, who came into the tournament on the back of winning the Shenzhen Open, was in a different class to the Italian, who at 31 is one day older than the Chinese player.

It was Pennetta's first quarter-final at Melbourne Park since making her tournament debut in 2003, and she appeared overawed by the occasion.

In contrast, the composed Li has been a consistently good performer on the Plexicushion courts over the past five years.

She has made the final twice, losing to Kim Clijsters in 2011 and then last year to Victoria Azarenka after dramatically twice rolling her ankle and briefly blacking out.

A blistering cross-court forehand gave Li a break point opportunity on Pennetta's opening serve on Rod Laver Arena, and a powerful backhand down the line sealed the game to give the Chinese star an early advantage.

The Italian should have pulled level in the next game, creating three break points, but she failed to convert any of them as Li held on.

It cost Pennetta dearly as the Chinese cranked up the pressure to go 3-0 in front, when a looping forehand from the 28th seed fell just outside the baseline.

Li's first serve was far more potent than Pennetta's and she raced to a 4-0 lead with her first ace of the match.

Pennetta was in trouble and losing confidence, with only 40 percent of her first serves going in, and a double-fault on break point compounded her problems as Li strengthened her grip at 5-0.

She managed to claw back a game on the Li serve and then held to give the set a more respectable look, but it only delayed the inevitable as Li served out for the set.

The flustered Pennetta then lost her opening service game on another double-fault, with the Italian kicking the ball away in disgust.

With the winning line in sight, Li easily held serve then broke again when Pennetta smacked a backhand into the net.

Li was on fire and she went 4-0 in front. Pennetta then saved two break points to stay alive before the Chinese number one wrapped it up.

Despite the defeat Pennetta, who missed last year's tournament after being sidelined for six months with a right wrist injury that needed surgery, is projected to return to the top 20 after the tournament.